Rolling mill and systems for facilitating the interchange of rolling-mill rolls

ABSTRACT

A ROLLING-MILL SYSTEM IN WHICH AT LEAST TWO ROLLING-MILL ROLLS ARE PROVIDED, BETWEEN THE THREADED GAP-ADJUSTING SPINDLE AND THE BEARING BLOCKS OF THE ROLLS, WITH A THRUSTBEARING STRUCTURE AND A SPACER BLOCK SWINGABLE OR SHIFTABLE FROM BETWEEN THE THRUST BEARING AND THE JOURNAL BEARINGS OF THE ROLLS TO FREE THE LATTER FOR REPLACEMENT. THE ROLL-CHANGING ARRANGEMENT COMPRISES A CARRIAGE SUPPORTING A PAIR OF ROLLS ADJACENT THE ROLLING-MILL STAND AND SHIFTABLE IN THE ROLLING DIRECTION INTO ALIGNMENT AXIALLY   WITH THE ROLL-ACCOMMODATING OPENINGS OF THE STAND, AND AN INSERTION CARRIAGE ENGAGEABLE WITH ONE END OF THE ROLLS FOR SUPPORTING SAME AND FEEDING THE ROLLS AXIALLY INTO THE STAND.

NOV. 9, 1971 w B M ETAL ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS Filed July 18, 1969 10 Sheets-Sheet 1 6 Walter m Brahm 3: Peter Zens v Theodor J. Sevenich xx 6 INVIiN'I'URS.

q R m Mom e y NOV. 9, 1971 w BRAHM ETAL 3,618,355

ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS Filed July 18, 1969 10 Sheets-Sheet 2 Pefer at R ss Attorney Walfer im Brahm Zens Theodor J. Sevenich INVIL'N'IORS.

NOV. 9, 1971 w BRAHM ETAL 3,618,355

ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS Filed July 18, 1969 10 Sheets-Sheet 5 Wa/fer im Brahm Perer Zens Theodor J. Sewn ch @708 a [NV/5N 1-0/6.

A 6RD Attorney NOV. 9, 1971 w BRAHM ETAL 3,618,355

ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS Filed July 18, 1969 10 Sheets-Sheet 4 INVENTOR. WALTER IM BRAHM PETER ZENS BY THEODOR J. SEVENICH gcul iRnu ATTORNEY 1971 w. BRAHM ETAL W ROLLING MILL AND SYSTEMS FOR. FACILITATING THE INTERCHANGE OF ROLLINGMILL ROLLS l0 Sheets-Sheet 5 Filed July 18, 1969 4 INVENTOR. WALTER IM BRAHM PETER ZENS BY THEODOR J. SEVENICH Nov Now ww mov mOv gzarl. 9 ATTORNEY 10 Sheets-Sheet 6 W. BRAHM ET AL Nov. 9, 1971 ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS Filed July 18, 1969 MM m 0 N n u c a a 3 b M 6 0 2 BNE T 2 3 2 V ES 4 m g I J R R iwm H H W T Y B F /k m Q a 4 O I m a 0 1 l A I ei a G 9b a l I G O 2 2 4 3 C... F

AT TORNEY w. BRAHM ET AL ROLLING MILL AND SYSTEMS FOR FACILITATING THE Nov. 9, 1971 INTERCHANGE OF ROLLING-MILL ROLLS l0 SheetsSheet V Filed July 18, 1969 40 fin IIIIIL fl. nu q SEVENICH INVENTORS, IM BRAHM ZENS WALTER PETER BY THEODOR J.

gCarI ATTORNEY NOV. 9, 1971 w BRAHM ETAL 3,618,355

ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS 1O Sheets-Sheet 8 Filed July 18, 1969 marl ATTORNEY 1971 w. BRAHM ETAL 3,618,35

ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS Filed July 18, 1969 10 Sheets-Sheet 9 INVENTORS, WALTER IM BRAHM PETER ZENS BY THEODOR J. SEVENICH m l To ATTORNEY NOV. 9, 1971 W, BRAHM ETAL 3,618,355

ROLLING MILL AND SYSTEMS FOR FACILITATING THE INTERCHANGE OF ROLLING-MILL ROLLS l0 Sheets-Sheet 10 Filed July 18, 1969 INVENTORS. IM BRAHM WALTER ZENS PETER THEODOR J. SEVENICH flCml ATTORNEY United States Patent Office 3,618,355 Patented Nov. 9, 1971 3,618,355 ROLLING MILL AND SYSTEMS FOR FACILITAT- ING THE INTERCHANGE OF ROLLING-MILL ROLLS Walter Brahm, im Mulheim (Ruhr), and Peter Zens and Theodor Josef Sevenich, Dortmund, Germany, assignors to Maschinenund Werkzeugbau GmbH, Dortmund-Hombruch, Germany Filed July 18, 1969, Ser. No. 843,129 Claims priority, application Germany, July 19, 1968, P 17 52 817.5; Mar. 19, 1969, P 19 13 771.4 Int. Cl. B21b 31/08 US. Cl. 72-238 21 Claims ABSTRACT OF THE DISCLOSURE A rolling-mill system in which at least two rolling-mill rolls are provided, between the threaded gap-adjusting spindle and the bearing blocks of the rolls, with a thrustbearing structure and a spacer block swingable or shiftable from between the thrust bearing and the journal bearings of the rolls to free the latter for replacement. The roll-changing arrangement comprises a carriage supporting a pair of rolls adjacent the rolling-mill stand and shiftable in the rolling direction into alignment axially with the roll-accommodating openings of the stand, and an insertion carriage engageable with one end of the rolls for supporting same and feeding the rolls axially into the stand.

FIELD OF THE INVENTION The present invention relates to rolling mills and, more particularly, to a roll assembly for rolling mills and a system for facilitating the interchange of rolling-mill rolls.

BACKGROUND OF THE INVENTION Rolling-mill arrangements have been provided heretofore in which a rolling train, consisting of a multiplicity of rolling stations or stands (stanchions), each provided With at least a pair of working rolls with a calibrated gap between them, successively receive a billet, strip, bloom or ingot to reduce the thickness thereof in a hot or cold condition and thereby lengthen the rolled member emerging from the rolling-mill train, while imparting a desired configuration or contour (profile) to the rolled body.

Each of the roll stands or stanchions (frame) comprises a pair of supports (coupled with a yoke or traverse) alongside the rolling path carrying the Working rolls and, in some cases, a pair of backing or support rolls which rotate in a sense opposite that of the working rolls and support the latter against the rolling pressures, egg. in a socalled four-high mil On the opposite ends of the working or support rolls, there are commonly provided respective journal bearings or blocks in which the rolls are rotatably received, but which are held in place and at which the desired interroll spacing is established, usually by means of a threaded spindle with a fine-pitch thread enabling adjustment of the working gap and the positions of the rolls.

This spindle, which may be driven by a variable-speed motor and transmission arrangement mounted upon the stand or station, can be backed off the working or support rolls only relatively slowly as a result of the fine pitch of the threads so that the freeing of a pair of rolls enables them to be withdrawn from the stand and/or replaced therein occupies considerable time. As a consequence of this time-consuming operation, an entire rolling train may be rendered inoperative for prolonged periods.

In general, between the bearing blocks or the individual rolls, which are mounted on and are replaced with the latter, and the threaded spindle which is used to establish the rolling gap, there is provided a thrust or step bearing which takes up the calibrating pressure and functions, in practice, as the member retaining the rolls in place, which is engageable with the journal bearings of the support rolls or the working rolls as described above.

Such journal bearings or bearing blocks are generally provided on both ends of the rolls and, similarly, the calibrating spindles and their thrust or stand bearings are likewise provided on each of the stanchions and may be driven by common motor or may be individually driven. The pressure spindle of the adjusting arrangement is journaled in the step or thrust bearing and is vertically shiftable in a threaded nut mounted in the respective stanchion and taking up the pressure applied to the spindle during rolling of a billet, bloom, ingot or other rollable member.

At the end of the spindle remote from the thrust bearing, a spline may be provided (or some other circular cross section, such as a square-section shaft) on which a worm gear is axially fixed so that the threaded spindle can move vertically therethrough but is continuously driven by the worm gear. The worm of the latter (or a starwheel in some arrangements) is driven by a motor through through a speed-reduction transmission which may or may not be continuously variable. The step or thrust bearing in its simplest form is constituted of a convex spherical bronze plate and a corresponding concave pressing surface of the spindle. In more modern arrangements, however, the thrust bearing is provided with conical roller bearings.

It has heretofore been necessary in rolling stations of the described type to bring the adjusting spindle fully into its upper end position, thereby freeing the working or counter-pressure rollers for replacing either the working rollers or the counter-pressure rollers or both. It is found, especially in the hot rolling of broad steel bands and the cold rolling of billets and blooms generally, that the fine pitch of the pressure spindle is such that it must be capable of precisely establishing dimensions of the order of millimeters. Accordingly, extremely long delays are common when the spindle must be withdrawn.

Also it may be pointed out that the actual removal and insertion of the rolls of a rolling-mill stand of the character described has heretofore been primarily a manual operation using hanger-type cranes or the like to support the rolls in alignment with the roll-receiving opening in the support and thereafter to shift the rolls into the stand. Cranes were also used to facilitate withdrawal of the rolls to be replaced. The entire operation, carried out primarily by hand, was also extremely costly and involved considerable down time of the rolling-mill installation, even when the roll replacement was carried out at a single station.

OBJECTS OF THE INVENTION It is, therefore, the principal object of the present invention to provide an improved system for replacing the rolls of a rolling mill and, especially, interchanging such rolls at a rolling station with a minimum of downtime and a maximum of speed.

A more specific object of this invention is the provision of a rolling-mill station, comprising a pair of support stanchions or stands, with improved means for facilitating the freeing of the working or support rolls so as to enable them to be rapidly replaced.

Still another object of this invention is to provide an arrangement whereby the rolls to be interchanged, in a station of the aforedescribed type, can be brought into position and removed from the roll frame with a minimum of manual effort and a maximum of speed.

Another object of this invention is to provide a rolling station of the general character set forth above in which the working or counterpressure rollers can be removed in the shortest possible time, i.e. the rolls to be removed can be freed with minimum effort and maximum speed, such that the downtime of the rolling station and of the entire rolling train can be reduced to a minimum.

SUMMARY OF THE INVENTION These objects and others which will become apparent hereinafter are realized, in accordance with the present invention, by an arrangement which provides the rolling station, which is formed with a pressure or calibrating spindle, with a thrust bearing interposed between the spindle and a bearing :block of a working or counterpressure roll mounted in the support frame, with at least one insert body which is shiftable, eg by hydraulic or mechanical means, between a position in which the insert body is interposed between the thrust bearing and the journal bearing or block of the corresponding roll, and the position in which it is fully withdrawn from between these members, thereby completely freeing the rolls for replacement or removal. In other words, the invention comprises a spacer or insert body which is interposed between the thrust bearings of the pressure spindles and the journal blocks built onto the adjustable working and/ or counterpressure rolls, the latter blocks generally being bearing bodies or otherwise enabling the rotation of the rolls within the support frame, the insert or filler bodies being withdrawable from the gap between the step or thrust bearing and the roll-carried journal blocks positioned at opposite ends of the rolls.

According to a more specific feature of this invention, a pair of such insert or filler bodies is swingably mounted for movement in opposite senses generally symmetrically with respect to an axial plane of the pressure spindle, upon the thrust or step bearing which may be provided at the end of the spindle confronting the roll. Thus, while it is possible to provide the insert bodies in the form of rectangular parallelopipeds and to shift them in a plane parallel to the surfaces of the parallel surfaces of the thrust bearing of the spindle and the journal bearings of the rolling-mill rolls, it is preferred to provide the insert bodies of concavo-convex configuration, i.e. with a concave surface corresponding to a segment of the surface of a right-circular cylinder, centered upon the axis of swing of the insert body and to pivotally mount these bodies upon the spindle hearing. The convex surface, which has the same center of curvature but a different radius, may correspond in configuration to the cylindrically concave surface of a seat formed on the journal bearing of the rolling-mill rolls. As previously indicated, two such insert bodies are provided between each pressure-spindle bearing and the corresponding roller-bearing body of the rolls and are swingable in mirror symmetry with respect to an axial plane of the spindle perpendicular to the axis of the rolls. This plane is preferably vertical. To insure symmetrical displacement of the insert body, they are coupled, e.g. via a pair of meshing gear segments journaled on the thrust bearings of the pressure spindle and swingable about the pivotal axes of the insert bodies and their centers of curvature. The concave and convex surface of the thrust bearing and the seat of the journal bearing of the rolling-mill rolls are, moreover, coaxial and centered upon the axes of swing of the insert bodies.

According to a more specific feature of this invention, the insert bodies at the opposite ends of the rolling-mill rolls are driven simultaneously with an equalization-type of actuator coupled in common to the insert bodies at both ends. An equalization-type actuator according to the present invention may make use of hydraulic cylinder having a single piston or a pair of pistons received in a common chamber such that the stroke of each piston is equal to the stroke of the other and the insert bodies are thereby swung simultaneously to the same degree. Another form of equalization-type actuator is a hydraulic cylinder whose cylinder body is coupled with one of the sets of insert :bodies while the piston is coupled with another. Coupling is effected in accordance with the present invention via levers swingably mounted on the respective thrust bearings and carrying the insert bodies and articulated or pivoted to connecting rods respectively coupled with the piston or pistons or the cylinder as indicated.

According to another feature of this invention, in place of the cranes heretofore employed to support the rolls prior to their insertion into the rolling-mill stand or stanchion, there is provided a head of the stand and in axial alignment with the roll-receiving part thereof, an axially shiftable roller-carrying insertion head engageable with the rolls and supporting same at one axial end in a cantilever manner. This head, which is axially shiftable to introduce the rolls into the rolling-mill stand, may also be employed to withdraw the rolls as will be apparent hereinafter. Preferably, both of the rolling-mill rolls of a rolling-mill pad are simultaneously engaged by the insertion head and shifted into the stanchion.

According to another feature of the invention, a carriage shiftable in the direction of rolling is provided along the track adjacent the stand to carry a pair of rolls, adapted to be inserted into the stand, such that it may be aligned with the insertion head and the rolls carried thereon brought by the head into the stand. A second axially movable roll-engaging head may be provided on the opposite side of the stand to withdraw the previous pair of rolls from the assembly. Preferably, upon release of the insert bodies of the first set of rolls, the latter are engaged by a removal head and withdrawn in the axial direction While the insertion head, provided with a hydraulic chuck, collet or gripper, engages the axial ends of the second pair, aligned on its carriage with the rollingmill support, and advances the second pair into the rolling mill-stand. The rolls are advanced into the stand to align the journal bearings built onto the ends of the sets of rolls with the thrust bearings of the pressure spindles so that the insert bodies can be then shifted into place and the desired calibration of the rolls established. The roll drive may then be coupled at the opposite ends of the newly inserted set of rolls.

Advantageously, the insertion head and, when provided, the removal head, may be formed with a pair of chucks or collets in a single threadedly shiftable and adjustable body to receive the axial ends of sets of rolls, the head being pivotal between a position in which they underlie the platform, stage or table (mill floor) upon which the carriage is mounted and corresponding substantially to the working plane of the rolling-mill installation. A cover plate overlies the insertion head and is swung upwardly to allow the latter to be positioned in alignment with the rolling-mill stand. A hydraulic power cylinder may be employed to swing the insertion head upwardly and, to this end, the insertion head may be provided upon a further carriage rolling along a pair of rolls or upon a rolling platform, a portion of the platform being swingable downwardly to accommodate the insertion head when the latter is to be removed from its operating position. In its upwardly swung position, this portion of the transport path of the insertion head is aligned with the remainder thereof in a horizontal plane to allow the rolls to be carried into the stand.

Still another feature of this invention resides in the provision on the carriage juxtaposed with the stand and shiftable in the rolling direction to bring a new set of rolls into alignment with the stand, of vertically displaceable hydraulic jacks or piston arrangements upon which the two sets of rolls is supported, to facilitate adjustment of the height of the rolls and the alignment with the stanchion. Advantageously, the carriage is formed with means enabling it to be lifted bodily from the assembly, e.g. by means of a crane, or otherwise re,-

moved together with the roll set and to be repositioned upon the track whenever it is necessary.

DESCRIPTION OF THE DRAWING The above, other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is schematic elevational view, partly in cross section, showing the roller frame of a rolling-mill installation provided with the swingable insert blocks of the present invention;

FIG. 2 is a cross section taken in a axial plane through a portion of the rolling-mill assembly embodying the invention;

FIG. 2A is a detail view, in elevation and partly in diagrammatic form, of the means for swinging the inside blocks out of their locking position;

FIG. 2B is an elevational view of the assembly taken at right angle to the view of FIG. 2;

FIG. 2C is an axial cross-sectional view through another embodiment of the thrust bearing arrangement according to the invention;

FIG. 3 is a diagrammatic elevational view showing the rolling-mill assembly prior to the insertion of the rolls therein;

FIG. 4 is a view similar to FIG. 3 of the assembly with the rolls in position of insertion into the assembly;

FIG. 4A is a vertical elevational view taken in the direction perpendicular to that of FIG. 3 and diagrammatically showing the alignment of the insertion head with the rolling-mill stand;

FIG. 4B is a detail view, partly in cross section and partly in diagrammatic form showing the means for engaging the rolls on the insertion head;

FIG. 5 is a plan view of another system for repacing the working roll of the rolling mill.

FIG. 6 is a cross section taken along the line VIVI of FIG. 5.

FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 5;

FIG. 8 is a cross-sectional view taken along the line VIIIVIII of FIG. 5;

FIG. 9 is a cross section through part of a mill frame in accordance with the present invention;

FIG. 10 is a view in the direction of arrow X (FIG. 8) of the apparatus shown in FIG. 9;

FIG. 11 is a view similar to FIG. 1 and partly in diagrammatic form of another embodiment of an insertblock arrangement according to this invention; and

FIG. 12 is a view of the arrangement of FIG. 11 in another operating position.

SPECIFIC DESCRIPTION FIGS. 1 and 2 show, partly diagrammatically, a rollingmill frame 1 with working rolls 2 and a yoke 3 spanning the opposite sides of the mill between the stanchions thereof and supporting the rolls at their opposite sides. As presented diagrammatically in FIG. 1, the upper working rolls 2 of the mill, e.g. a two-high mill in the system of FIGS. 1 and 2, is formed at opposite axial ends with built-on bodies 4 constituting the journal bearings for the central roll portion 2a.

The upper surfaces of the journal blocks 4 are formed with cylindrically concave seats 15, the purpose of which will be set forth in greater detail hereinafter.

The assembly is provided with a pair of adjusting devices 5 in the form of threaded spindles having at their bottom ends step or thrust-bearing arrangements 8, the journal blocks 4 further co-operating with a hydraulic roll-relieving device as presented, for example, at 6 in FIG. 2.

As shown in greater detail in FIG. 2, the adjusting device 5 comprises a pressure spindle 7 which is formed at its end with a thrust-bearing assembly 8, and is threadedly 6 received in a pressure nut 9 anchored in the head 3a of the yoke 3 b a plate 3b partly overlying the cylinder recess 3c, receiving this nut 9. The latter is formed with a noncircular outer peripheral configuration while the recess 3c is of complementary configuration to ensure nonrotation of member 9.

The threaded spindle 7, whose threaded shank is represented at 7a, also is formed with a spline portion :11 axially shiftable but rotatably entrained in a worm gear 10a forming part of a spindle drive 10, the remainder of which may include a worm meshing with the worm gear 10a, a stepless adjustable-speed high-torque transmission, and an electric motor mounted upon the support frame in accordance with the usual techniques.

Thus rotation of the worm gear 10a will lead to rotatable entrainment of the spindle 7 which, however, is free to move axially within the nut 9 and thus will advance or retract the spindle 7 in the vertical direction to establish the operating spacing between the rolls upon which the spindle bears via the thrust bearing and the journal blocks 4 associated with each roller and constituting part of the roller assembly upon replacement or discharge of the rollers.

At its lower end, the spindle 7 is provided with a flange 7b whose axially concave lower surface 8c engages a bronze bearing plate 8d of upwardly convex configuration, the plate 8d being received in a bearing housing 8e closed by a plate 8 overlying the flange 7b.

According to this invention there is provided between each thrust bearing 8 of the pressure spindle 7 and the journal bearing 4 of the working roll 2, a pair of insert filler bodies 12 which are shown in position in FIG. 2 and which can be swung out of the gap 13 between the thrust bearing 8 and the journal bearing 4 as represented in dotdash lines in FIG. 2 but shown in solid lines in FIG. 1.

Preferably, two such insert bodies are provided between each thrust bearing and the respective journal bearing, the insert bodies 12 being shiftable in mirror-symmetrical relation with respect to an axial plane P of the spindle 7 lying perpendicular to the axis A of the roll 2. As can be seen in detail in FIGS. 1 and 2A, each thrust bearing 8 is formed with a pair of surfaces 14a and 14b symmetricall with respect to the plane P and corresponding to the surface of a right-circular cylinder centered upon the respective axes A and A lying in a plane P parallel to the axis A of roll 2 but perpendicular to plane P and the pressure spindle 7.

The surfaces 14a and 14b which adjoin at a node 140, have radii of curvature R. The juxtaposed surfaces, e.g. surfaces 15a and 15b of FIG. 1 of the journal bearings 4 built onto the rolls 2 at their opposite axial ends have radii of curvature R and conforming to segments of right-circular cylinders coaxial with the segments 14a and 14b. Each of the insert bodies 12 shown in FIGS. 1, 2, 2A and 2B is of concavo-convex configuration with an upper surface 12a, for example, corresponding to a segment of a right-circular cylinder coaxial with the corresponding surfaces 14a and 15a and with the radius of curvature R (FIG. 2A) equal to the radius R previously mentioned. The convex surface 12b of each insert body has a radius of curvature R equal to the radius R; of the seat 15a.

The insert bodies 12 are respectively swin'gable about the axes A and A on pivots 16 extending therealong via arms 8a pivotally connected at ab with each of the insert bodies. As shown in FIG. 2B, two such arms 8a, flanking the insert body, are coupled therewith. The displacement of the insert bodies 12 is effected by a lever linkage \18, articulated to one of the arms shown in FIG. 2A at 18a, by means of an equal-stroke cylinder '19 coupling the insert bodies at opposite axial ends of each roll as represented in FIG. 1 so that the insert bodies are displaced simultaneously in the embodiment shown in FIG. 1. The far lever 108a is formed as a bellcrank lever with an arm 108a (left-side of FIG. 1) connected to the rod 18 which passes through the cylinder 19, is affixed to the piston 19a, and is articulated to the near arm 108a" of the bellcrank lever rotating in the same sense at the right-hand side of the rolling mill. The cylinder 19 is, in this case, mounted in a bracket 1% on a yoke or cross bar 3 of the rolling-mill stand.

As is also shown in FIG. 1, 2, 2A and 2B, the rotation of the levers and withdrawal of the insert bodies 12 of each thrust bearing 8 is synchronized by means of a pair of meshing gear sectors 17 respectively connected with the levers 8a. Thus, when the piston 19a in FIG. 1 is shifted to the right, the insert bodies 12 of each thrust bearing 8 will move toward one another to bring these insert bodies into position as spacers or fillers between the thrust bearing and the juxtaposed seats of the journal bearings 4 of the roll 2. A displacement of the piston 19a to the left, e.g. into its extreme position as shown in FIG. 1, will cause the insert bodies 12' of each bearing 8 to free the rolls for removal and/ or replacement.

In the use of the system illustrated in these figures, the roll-loading means 6 of the rolling mill is relieved of the hydraulic pressure maintaining the desired rolling force, the insert bodies 12 are swung rapidly out of the gap 13, and the rolls are thereby placed in their upper-most position enabling replacement and withdrawal. Backing-off of the spindles 7 is not necessary nor does the device experience the considerable down time associated with slowly operating spindles when they must be withdrawn by rotation to free the rolls.

In FIG. 2C, we have shown another step of thrustbearing arrangement in accordance with the present invention and which can, of course, be provided with the insert bodies described in connection with FIGS. 2, 2A and 2B. In this arrangement, the bearing body 208 is formed with a chamber 208' receiving the flat flange 207b of a spindle 207 the threaded portion of which is shown at 207a. Above and below the flange 207b, there is provided a respective conical-roller thrust bearing assembly 208a and 208b, the assemblies being held in place by a plate 2081). The body 208 of the bearing assembly is held fixed when the insert bodies are clamped between each thrust bearing and the journal bearings of the rolling mill rolls.

FIGS. 11 and 12 show a modified arrangement operating under the same general principles in which the roll 302 is provided at each end with a journal bearing 304, the upper surface 304a of which is horizontal and parallel to a juxtaposed planar surface 308a of the thrust bearing 308 at the end of a pressure spindle 307 which has the function and construction of the spindle 7 described above. In this embodiment, however, a pair of insert blocks 312 is provided with rectangular parallelopipedal configuration. The insert blocks 312 are shiftable in a horizontal plane parallel to the roll axis and perpendicular to the spindle 307 by a hydraulic cylinder 319 via arms 316 coupling the pistons of the cylinder with the insert blocks 312. The cylinder 319 may be supplied with hydraulic fluid by a valve 319a. from a pump 31911 and a reservoir 3190, a pressure-relief valve being provided between the output side of pump 3191; and the reservoir as shown at 319d. In FIG. 12, the blocks 312 are shown fully withdrawn to free the roll 302 and provide rapidly a gap 313 between the thrust bearing 308 and the journal bearing 304.

FIGS. 3 and 4 illustrate a system for facilitating the removal and insertion of pairs of working rolls of a fourhigh rolling mill in accordance with the present invention. The rolling mill stand 400 illustrated in these figures comprises a pair of uprights 400a and 4001) of generally triangular configuration (see FIG. 4A) across which extends a yoke or traverse member 403 carrying a gear 41% which drives a shaft 410s carrying the worms for rotating worm gears such as are shown at 10a of corresponding spindles 7 to bear against the working rolls 402 or a pair of backing or support rolls 402a mounted in the stand.

8 The rolls are released by the use of insert blocks of the type discussed previously and at the left-hand side of the rolling mill assembly of FIG. 3, the working positions of the rolls are shown for the formation of strip or bands, while the released position of the rolls is presented at the right-hand side of the plane P The working rolls 402 are driven by sockets 402b engaging keys 402c at the left-hand axial hands of the rolls 402. While the arrangement of FIGS. 3, 4, 4A and 4B is used, as described, to change only the working rolls 402, it will be understood that the support rolls 402a can be replaced by similar means and/ or both sets of rolls may be replaced at once, using a common insertion head.

Ahead of the assembly 400, there is provided a movable insertion carriage 20, shiftable on the rollers 25 along a track 25a, 25b in the axial direction, i.e. parallel to the axis of the rolls 402 and in axial alignment with the roll-receiving station 4006 of the mill as can be seen in FIG. 4A. To receive the set of rolls to be replaced, or to accommodate the set of rolls to be inserted, there is provided a support plate represented at 21, 22, the former being shown in FIG. 4A to the left of the rolling mill 400 as accommodating a set of rolls 402' previously withdrawn from the mill while the latter carries a set of rolls 402" adapted to be introduced in a roll-changing sequence.

The roll-changing head 20 comprises, in accordance with this invention, two roll-engaging sleeves 2 3, 24, on a common support 20a to enable the sleeves 23, 24 to be raised and lowered jointly (arrow B) by a control such as a leadscrew 2012 provided with a handle 200 (best seen in FIG. 4). The sleeves 23 and 24 are hydraulically actuatable chucks or collets engageable with cylindrical projections 402d (FIG. 3) and may have a construction equivalent to that shown in FIG. 4B. In this figure, the sleeve 23 is shown to be mounted upon a bar 23a projecting from the vertically shiftable support 20a and to be provided with a plurality of jaws 23b axially shiftable (arrow C) against forwardly converging rams 23c such that the jaws are wedged inwardly against the force of a spring 23d to lock the respective cylindrical portion 402d in place. The jaws 23b are axially displaceable by a piston 23e upon the introduction of hydraulic fluid under pressure to the chamber 23 The latter is supplied with the fluid via a passage 235 in its support shank, a control valve 2311, a pump 23i and a reservoir 23j. A pressure relief valve 23k forms a bypass from the pump 231' to the reservoir to prevent overloading.

The roll-changing sleeves .2'3, 24 are disposed with a fixed distance between them corresponding to the positions of the roll shafts and are vertically adjustable as has been stated earlier. The rollers 25, on which the carriage 20 runs can be journaled eccentrically to provide for vertical adjustment of the sleeves 23 and 24. The carriage 20 is mounted upon a swingable platform 27 which normally lies below the plane of the mill floor '26 and is covered by a flap 29 pivoted at 29a to the support structure. The platform 27 is, in turn, swingable by means of hydraulic force from a power cylinder 28, the cylinder 28 having a piston rod 28a coupled at a lug 28b to the platform 27. When the insertion head 20 is retracted (FIG. 3), the cover 29 lies in a horizontal plane parallel to the mill floor and permits passage of personnel and equipment.

Each of the plates 22, shown to be mounted on a guide rail 30 ahead of the stand 400 in the direction parallel to the rolling direction (arrow D) is provided with a pair of roll-receiving members which are vertically adjustable and are represented in the embodiment of FIGS. 3 and 4 as hydraulic jacks 31 the pistons 31a of which carry seating blocks 32'. When two rolls constitute a set, as illustrated in FIG. 4A, a yoke arrangement 32a may be carried by the seating block 32 to support the upper rolls. A hangartype crane 30a whose chains are shown at 30b is shiftable across the floor 26 and is provided with hooks 30c engageable with eyes 22a to enable the platforms 21 and 22 to be mounted upon the transport table 30 for replacement of the sets of rolls.

First the insertion head 20 is used to withdraw the rolls 402" onto the platform 21 which is then rolled aside in the direction D to permit a second platform '22, already carrying the new set of rolls 402", to be positioned in alignment with the sleeves 23 and 24 and the roll-receiving portion 4000 of the stand. After the new set of rolls has been positioned in the stand, the spindle 407 may be advanced to establish the gap between the working rolls once the insert bodies 412 have been brought between the thrust bearing 408 and the journal bearings of these rolls as described in connection with FIGS. 1 and 2.

In FIGS. -l0, there is shown a further embodiment of the invention for the replacement or interchange of the working rolls of a mill, e.g. a four-high mill as shown in FIGS. 3 and 4 or a two-high mill of the type discussed in connection with FIGS. 1 and 2. In this arrangement, there is provided, along the free side of the rolling mill frame 501, i.e. the side of the frame 1 opposite the driving ends of the mill rolls, a plate 33 (one for each set of rolls of the rolling-mill train, two such mill stations being illustrated in FIGS. 5 and 6). The plate 33, which is mounted upon Wheels 37, carries a set of new working rollers 502a upon a support structure 531, which may be vertically adjustable as shown for the hydraulic jacks 3 1 of FIGS. 3 and 4. The new set of rolls 5012a is alignable axially with the roll-receiving compartment 5000 of the rolling mill, from which the previously used set of working rolls 502!) has been withdrawn. In the imaginary extension of the center line of the rolling mill assembly 501, ahead of the plate 533, there is provided a shifting arrangement 34 in the form of a hydraulic cylinder. When this cylinder 34 is not required, it lies beneath the cover 529 which is pivotally mounted at 529" in a well 529" in the floor 526 of the mill. To raise the covers 529 and thereby position the hydraulic ram 34 such that the ram heads 34a are engaged with a new set of rolls 5021: upon shifting of the platforms 533 to the left, a hydraulic jack 528 is provided. The ram head 34a is hydraulically actuatable (see sleeve 24 of FIG. 4B) to enable the ends of the previously used set of rolls to be engaged and withdrawn.

As shown in FIGS. 6 and 7, the platforms 533 lie at the level of the mill floor 52'6 upon a rail assembly 36, 3'8 engaged by the wheels 37 mounted upon the chassis 35 of these platforms. The rails as illustrated in FIG. 7 are constituted by grooves in which the wheels 37 are received. The hydraulic cylinder 39 is provided such that its piston is coupled at 39a with the left-hand platform 533 while the cylinder body is fixed, stops 40 being pro- 0 vided at the ends of the track 36 to define the limits of movement of these platforms.

The platforms 533 are formed with openings 41 into which the hooks (22a) of a hangar-type crane can be inserted to lift the platforms from the tracks for replacement with platforms carrying the desired working rolls. 1

The platforms 533 are also provided in succession with downwardly turned hooks 42. adapted to be received in upwardly opened channels 43 of an adjacent platform 533 to couple two or more platforms together as shown in FIG. 6. In fact, the number of platforms hooked together in this fashion can equal the number of roll assemblies of each rolling-mill train.

When it is desired to exchange or replace the working rolls 502 etc., between the upper and lower journal blocks 504 of the working rolls, spacers are inserted in gaps corresponding to that shown at 44 to hold the backing or support rolls 44a and 44b apart. The hydraulic cylinders 45 of the rolling frame 1 are actuated to shift the guide bars 46 which are raised and lowered by the cylinder, to bring the guide bars into engagement with a stop 47 and lift the working rolls 2. The guide bars 46, which extend along the rolls, are coupled via links 48 and levers 49 with the piston rod of cylinder 45 (see FIG. 9). The

lifting of the lower rolls creates a gap between it and the lower support rolls and the working rolls to be removed have their skids '50 on each side of the lowermost rolls brought to the level of the upper edge of the platform 533 to allow the rolls to ride onto the latter. Upon decoupling of the working rolls from the drive, the piston 528 raises the cylinder 34 so that its chuck engages the rolls and withdraws it from the mill as described in connection with the embodiment of FIGS. 3 and 4 on the skid 50 onto the plate 533 without the need of a gap between the mill frame 501 and the platform 36-. Rapid replacement is permitted by a slight movement of the platform 533 to align the new set of rolls with a working-roll position of the tracks and then feeding rolls axially into the latter by the hydraulic cylinder 34. A shaft 51 links the levers 49 to ensure joint movement at both ends of the roll.

We claim:

1. A rolling-mill assembly comprising:

a rolling-mill stand adapted to receive a plurality of rolling-mill rolls; a plurality of rolling-mill rolls at least one of which is removably mounted in said stand;

a pair of pressure spindles threadedly mounted on said stand at opposite ends of said rolls and drivable to shift respective spindle ends toward and away from at least one of said rolls for establishing a rolling gap between working rolls of said stand; a thrust bearing on each of said spindles juxtaposed with the respective end of one of said rolls; and

at least two insert bodies receivable between each of said thrust bearing and the respective roll end and removable to free said roll end Without fully backing off said spindle, the insert bodies between each thrust bearing and the respective roll end being displaceable in opposite directions in mirror symmetrical relationship with respect to an axial plane of the respective spindle.

2. In a rolling-mill installation comprising a roll stand adapted to replaceably receive a plurality of rolling-mill rolls, the improvement which comprises an insertion head 'engageable with a pair of rolls to be inserted into said stand at one axial end of the roll and movable axially of said stand to introduce the engaged rolls into said stand, each of said rolls having a respective shank at a corresponding extremity thereof, said insertion head being formed with a pair of sleeves receiving said shanks and supporting said rolls and a platform shiftable in the rolling direction and accommodating at least one set of rolls to be aligned with said head for introduction thereby into said stand, the mill floor being formed with a well receiving said head in a retracted position and with a flap overlying said well flush with said mill floor in a retracted position of said head.

3. The assembly defined in claim 2 wherein said insert bodies are swingably mounted on the respective thrust bearings.

4. The assembly defined in claim 3 wherein each of said thrust bearings is provided with a pair of convex surfaces coaxial with the swing of the respective insert body, said insert bodies each having a concave surface slidably aligned and coaxial with the associated convex surface of the respective thrust bearing.

5. The assembly defined in claim 4 wherein said ends of said common roll are formed as journal bearings and are provided with concave surfaces coaxial with the respective convex and concave surfaces of said bearings and said insert bodies having a concavo-convex configuration.

6. The assembly defined in claim 3 wherein the insert bodies of each of said thrust bearings are coupled together for synchronous movement.

7. The assembly defined in claim 6, further comprising a pair of meshing gear segments mounted on each of said thrust bearings and swingable about the pivotal axes of said insert bodies respectively, a generally radial arm affixed to each gear segment and to the respective insert bodies, and means for displacing one of the arms of each thrust bearing.

8. The assembly defined in claim 7 further comprising a common drive for one of said arms of each of said thrust bearings.

9. The assembly defined in claim 8, further comprising a platform shiftable alongside said stand in the direction of rolling and carrying a roll to be introduced into said stand upon withdrawal of the movably mounted roll, an insertion head having a sleeve hydraulically engaging one end of said roll on said platform and shiftable in the axial direction of said roll for inserting same into said stand.

10. The assembly defined in claim 8, further comprising a platform shiftable alongside said stand and adapted to receive at least one roll upon its removal therefrom and carrying a new roll to be inserted in said stand, a hydraulic ram normally retracted below the mill floor but elevatable and alignable with the mill stand and said new roll for engaging the latter and introducing same into said stand.

11. The assembly defined in claim 8, further comprising a platform shiftable alongside said stand, means for withdrawing a removable roll from said stand in the axial direction of the rolls, and means for lifting said removable roll to enable it to ride onto said platform.

12. The installation defined in claim 2 wherein said insertion head is elevatable into axial alignment with the rolls disposed ahead of said stand.

13. The installation defined in claim 12 wherein said sleeves are a fixed distance from one another and are jointly displaceable vertically to adjust the heights of said sleeves.

14. The installation defined in claim 13 wherein said sleeves are formed as hydraulically operable clamps receiving said rolls.

15. The assembly defined in claim 2, further comprising a power cylinder in said well acting upon said head for raising it above said mill fioor in an operating position of said head.

16. The improvement defined in claim 15, further comprising crane means for displacing said platform bodily with at least one set of rolls mounted thereon.

17. In a rolling mill comprising a plurality of stands in spaced relationship, each adapted to receive a plurality of rolling-mill rolls, the improvement which comprises:

platform disposed alongside said stand and shiftable in the rolling direction for accommodating a set of rolls withdrawn from said stand and a set of new rolls to be introduced into said stand;

a hydraulic ram normally recessed in the mill floor alongside said stand and engageable with rolls on said platform to advance the same into said stand and withdraw rolls from said stand, respectively;

a rail extending along one side of said stands, each of said stands being provided with a respective one of 12 said platforms, said platforms riding on said rails; and

hydraulic means for elevating said ram above said mill floor to shift said rolls.

18. The improvement defined in claim 17, further comprising mating means interconnecting said platforms for joint movement.

19. An apparatus for replacing rolling-mill rolls of a rolling-mill stand such as a four-high rolling-mill stand, said apparatus comprising:

roll-gripping means disposed alongside said stand and provided with a pair of roll-engaging sleeves shiftable axially with respect to the rolls of said stand for seizing a pair of such rolls and withdrawing them from said stand;

a well provided in the mill floor for receiving said roll-gripping means;

a hydraulic cylinder engaging said roll-gripping means for raising same above the mill floor and lowering said roll-gripping means into said well, selectively;

a pair of roll supports disposed between said roll-gripping means and said stand and spaced apart axially with respect to said rolls for receiving same upon withdrawal of rolls from said stand and prior to introduction of rolls into said stand by said rollgripping means; and

means mounting said supports for displacement alongside said stand in the rolling direction.

20. An apparatus as defined in claim 19 wherein said means mounting said support for displacement alongside said stand in the rolling direction comprises a plate engageable by a portal crane, and hydraulic cylinder means for adjusting the levels of said supports.

21. An apparatus for replacing rolling-mill rolls of a rolling-mill stand such as a rolling stand in a continuousband rolling installation, said apparatus comprising:

roll-support means adjacent said stand and movable in the rolling direction, said roll-support means being alignable with said stand for receiving rolls therefrom and insertion of rolls into said stand;

axially shiftable roll-engaging means aligned with said stand for inserting rolls on said support means into said stand and withdrawing rolls from said stand onto said support means; and

means for raising said roll-engaging means above and for lowering said roll-engaging means below the floor of said mill.

References Cited UNITED STATES PATENTS 2,260,762 10/1941 Warrington et al. 72238 3,190,099 6/1965 Sieger et al 72238 3,217,526 11/1965 Wilson et al. '72 239 3,323,345 6/1967 Lyle et al. 72239 TRAVIS S. MCGHEE, Primary Examiner 

